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Photo Technical

Lag time on digital cameras can be a maddening issue – A36

One of the most annoying aspects of owning a pocket or point and shoot digital cameras for me is the lag time, that is, the time it takes from when you press the shutter button to when the picture is actually taken.

My first pocket digital was the Canon S50.  It was a 5 megapixel camera, 2600X1950 pixel resolution, which when divided by the optimum print resolution of 300 pixels, will output a quality 8.5”X6.5” print without a software enhancement.  This was acceptable, especially going 4+ years when I purchased this camera, and considering seldom do we need anything larger than an 8X10 print.

In discussing megapixels and pixel resolutions I always have to re-state to not overlook the size of the imaging sensor in relation to a quality output.  In case of the Canon S50 the CCD sensor is 1/1.8, about 23% the size of my Canon 5D that has a full 35mm size sensor.  Nevertheless, it was a better than average size for a pocket digital.  The thing to keep in mind is that both the  number pixels and the size of the pixels impact quality.

My purchase decision for the S50 was also based on its ability to take RAW as well as JPG files.  To understand the former it helps to explain the latter first. When you take a shot in the JPG file format the camera uses built in software to throw out information to make the file smaller and the processing faster.

In an oversimplified explanation it works something like this; all tones and colors are made up of numerical 0’s and 1’s to represent them.  If your shot has a great deal of blue sky the internal software can represent this large area with a small numerical interpolation to represent the vast blue sky.

With RAW no such interpolation is made.  All the information in the photograph taken remains and nothing is discarded.  This is useful in post production handling and enhancement of the image.  Since there is more information in the RAW as opposed to the JPG you can do more to the former without degrading it.  Doing more means adjusting colors, sharpening, restoring highlights or shadows, and many other adjustments.

This RAW vs. JPG is a mute point for most sailors who just want simplicity and have fun getting some snaps of parties, friends, and travel scenes.  For them a JPG’s only camera works great.  There’s no fuss and a large selection of cameras to choose from.  On the other hand, the serious photo hobbyist may want to consider a camera with RAW capabilities, but then there are few cameras to select from.

That the S50 had a 28mm lens was another sales point for me, as I find it very useful to have a true wide angle lens.  I can say with near certainty that all the photographs you see in yachting are taken with wide angle lenses.  A wide angle is great, a must for tight spaces common on a yacht or sailboat.

Another advantage of a wide angle lens is its great depth of focus, meaning most everything taken stays in focus.  Of course, as mentioned in other articles the aperture setting also has an effect on the focus range.

A disadvantage of wide angle lenses is that they distort space.  This is most noticeable nearer the right and left edges of the frame.  You will notice walls leaning in and skewed.  With a 28mm it is not overly severe in this regard, but with anything wider like a 24mm or 17mm it becomes troublesome and challenging.  Not to worry, very few compact cameras even offer a 28mm.  They are usually 35mm or 39mm or the like.  Not for me, I always need a lens capable to be a 28mm wide angle and if it zooms X4 to a 112mm, I’m satisfied.

The problem for boaters is dealing with either very tight spaces or scenes and subjects that are far away and you can’t easily get closer to.  You may desire a X10 zoom from 28mm to 280mm, but unfortunately you can’t have everything in one pocket camera, and they do not allow for interchangeable lenses.  [We can explore the options in the next article, and I will also get into how to read a camera specifications chart.  I actually started this article with that latter plan.]

So I had the camera with a suitable (at that time) resolution, able to take images with different file options, with a wide angle lens, but was I happy with this camera?  No, not completely.  It had one big problem… shutter lag.

To discuss this topic I did some digging and found to my dismay the S50 lag was over 1 second.  That’s horrible, and it was!  I checked on some cameras I mentioned last time, the Panasonic DMC LS80 and LS75, Samsung Digimax S760, Canon Powershot A470, and these are their lag times for a single and 5 consecutive shots – 0.49 & 16.17, 0.40 & 18.67, 0.30 & 8.37, 0.28 & 7.60.

I’ll have to continue on this topic next time.  Right now I need permission to go ashore and based on these stats get me a Powershot A470.